Portion of a burner assembly



FIG. 1 is a front perspective view of a portion of a burner assembly showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an alternate side view thereof; and,

FIG. 6 is a top view thereof.

The broken line showing of various regions, including the unshaded areas therein, is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a burner assembly, as shown and described. 